The terms “Semi tractor-trailers” or simply “tractor-trailers” commonly refer to the combination of a tractor truck and one or more semi-trailers used for over road transportation of goods and materials. Tractor trucks generally pull a single semi-trailer, but may also pull two or more shorter trailers, commonly known as “pups.” Aerodynamic drag is a major contributor to fuel consumption in tractor-trailer commerce, especially at speeds above 40 MPH. Aerodynamic improvements can contribute to fuel savings and provide significant cost reduction.
Fixed air foils and fairings are often mounted to tractor trucks and trailers to provide some degree of aerodynamic improvement. These fixed air foils and fairings are mounted to the tops, sides and bottoms of both tractor trucks and trailers, but cannot cover or enclose the space or “gaps” between the tractor truck and trailers, or between connected trailers and pups. The gaps between the tractor trucks and trailers and between connected trailers is necessary for the articulation of the tractor-trailer; however the gaps between tractor trucks and trailers are a particular source for aerodynamic drag.
A variety of rigid panel fairing systems have been developed to cover or enclose the gaps between tractor trucks and trailers. Rigid panel fairing systems use a variety of mechanical arms, linkages, tracks, slides, motors and actuators to manually or automatically move large rigid fairing panels between stowed and deployed positions enclosing the gaps. Heretofore, such rigid panel fairing systems have met limited success due to their mechanical complexity, functionality, reliability and cost. Structural variations in the design of individual tractor trucks and trailers also make incorporating the use of rigid panel fairing systems difficult. Moreover, rigid panel fairing systems generally cannot completely cover or enclose the gaps between tractor trucks and trailers because of the varying setup of the tractor trucks kingpin, which is generally set for each trailer depending on its intended cargo load.